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    <title>Document</title>
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    <script>
        const arr1 = ['a', 'b',[1,2]];
        const arr2 = ['c'];
        const arr3  = [...arr1,...arr2]
        // 这里很奇怪，我在js在线编辑器输出的就是1，这个电脑太垃圾？？？？？
        console.log(arr3); // 这里在修改前，输出的结果也是['a','b',[9999,2],'c']
        console.log('-------------------------------')
        arr1[2][0] = 9999 // 修改arr1里面数组成员值
        console.log(arr3) // 影响到arr3,['a','b',[9999,2],'c']
    </script>
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